"Steven M. Bellovin" <smb@research.att.com> writes:

> It's also worth noting that according to my reading, Schnorr's patent applies 
> only to smart-card systems.  See
> http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='4,995,082'.WKU.&OS=PN/4,995,082&RS=PN/4,995,082
> for the full text, but claim 1 starts:
> 
> 	1. In a method for mutual identification of subscribers in
> 	a data exchange system working with processor chip cards
> 	and using identification data coded into the cards by a
> 	card-issuing center including subscriber-related public
> 	keys and stored in the respective chip cards along with
> 	private keys which have a logical relationship to the public
> 	keys, whereby random number-dependent check data are
> 	exchanged between the subscribers, comprising the steps of:
> 
> etc.  All claims follow from this one.  I have no idea if smart cards
> are in the design space for NetBSD, or if there are other patents; this
> is the only one I've seen cited.

Schnorr admits to screwing up with the filing of his US
Patent. Despite a number of patents to the contrary, US patent lawyers
still have a culture of unease about the USPO's reaction to software
patents. This is why for example that the original zip patent was
described in terms of PLA's etc, and not software algorithms.

It is worth noting that Schnorr's euro-patents are broarder.

Julian.